[CI] Refactor the GHA code that nightly builds

by delegating the schedule trigger to one file per branch.

.github/workflows/root-630.yml

@@ -3,7 +3,7 @@ name: 'ROOT 6.30'
 
 on:
   schedule:
-    - cron: '25 14 * * *'
+    - cron: '0 1 * * *'
 
   workflow_dispatch:
     inputs:

.github/workflows/root-ci.yml

@@ -2,9 +2,6 @@
 name: 'ROOT CI'
 
 on:
-  schedule:
-    - cron: '0 1 * * *'
-
   # https://github.com/root-project/root/pull/12112#issuecomment-1411004278
   pull_request:
     branches:

.github/workflows/root-master.yml

@@ -0,0 +1,38 @@
+
+name: 'ROOT Main'
+
+on:
+  schedule:
+    - cron: '0 1 * * *'
+
+  workflow_dispatch:
+    inputs:
+      incremental:
+        description: 'Do incremental build'
+        type: boolean
+        required: true
+        default: true
+      binaries:
+        description: Create binary packages and upload them as artifacts
+        type: boolean
+        required: true
+        default: false
+      buildtype:
+        description: The CMAKE_BUILD_TYPE to use for non-Windows.
+        type: choice
+        options:
+        - Debug
+        - RelWithDebInfo
+        - Release
+        - MinSizeRel
+        default: Debug
+        required: true
+
+jobs:
+  run_nightlies:
+    uses: root-project/root/.github/workflows/root-ci.yml@master
+    with:
+      base_ref: 'master'
+      head_ref: 'master'
+      ref_name: 'master'
+    secrets: inherit